/**
 *  CONNECT.c -- Connect-the-Dots Mouse Demo Program
 *          (c) Charles Petzold, 1998
 */

#include <windows.h>

# define MAXPOINTS 10

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow)
{
    static TCHAR szAppName[] = TEXT("Connect");
    HWND hwnd;
    MSG msg;
    WNDCLASS wndclass;

    wndclass.style = CS_HREDRAW | CS_VREDRAW;
    wndclass.lpfnWndProc = WndProc;
    wndclass.cbClsExtra = 0;
    wndclass.cbWndExtra = 0;
    wndclass.hInstance = hInstance;
    wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
    wndclass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    wndclass.lpszMenuName = NULL;
    wndclass.lpszClassName = szAppName;

    if (!RegisterClass(&wndclass))
    {
        MessageBox(NULL, TEXT("This program requires Windows NT!"), szAppName, MB_ICONERROR);
        return 0;
    }

    hwnd = CreateWindow(szAppName,
                        TEXT("Connect-the-Points Mouse Demo"),
                        WS_OVERLAPPEDWINDOW,
                        CW_USEDEFAULT,
                        CW_USEDEFAULT,
                        800,
                        800,
                        NULL,
                        NULL,
                        hInstance,
                        NULL);
    ShowWindow(hwnd, iCmdShow);
    UpdateWindow(hwnd);

    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    static POINT pt[MAXPOINTS];
    static int iCount;
    HDC hdc;
    int i, j;
    PAINTSTRUCT ps;

    switch (message)
    {
    case WM_LBUTTONDOWN:
        iCount = 0;
        InvalidateRect(hwnd, NULL, TRUE);
        return 0;
    case WM_MOUSEMOVE:
        if(wParam & MK_LBUTTON && iCount < 1000){
            pt[iCount  ].x = LOWORD(lParam);
            pt[iCount++].y = HIWORD(lParam);

            hdc = GetDC(hwnd);
            SetPixel(hdc, LOWORD(lParam), HIWORD(lParam), 0);
            ReleaseDC(hwnd, hdc);
        }
        return 0;
    case WM_LBUTTONUP:
        InvalidateRect(hwnd, NULL, FALSE);
        return 0;

    case WM_PAINT:
        hdc = BeginPaint(hwnd, &ps);
        
        SetCursor(LoadCursor(NULL, IDC_WAIT));
        ShowCursor(TRUE);
        for(i=0; i<iCount-1; i++) {
            for(j=i+1; j<iCount; j++) {
                MoveToEx(hdc, pt[i].x, pt[i].y, NULL);
                LineTo(hdc, pt[j].x, pt[j].y);
            }
        }
        ShowCursor(FALSE);
        SetCursor(LoadCursor(NULL, IDC_ARROW));
        EndPaint(hwnd, &ps);
        return 0;

    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;
    }
    return DefWindowProc(hwnd, message, wParam, lParam);
}